Hidden Cameras Capture World of the Rare and Wild

By ANDREW C. REVKIN

Published: July 31, 2001

In the steamy Indonesian darkness, a Sumatran rhinoceros slops through a swamp. Click.

High on an icy ledge in the Himalayas, a snow leopard sniffs a scent mark on a rock. Click.

In hills near San Diego, a mountain lion lopes along a trail. Click.

From the depths of South Asian rain forests to the shrinking patches of wilderness tucked in California's megalopolises, automated cameras have become a preferred tool of conservation biologists trying to study rare and reclusive animal species.

Starting in the early 1900's, biologists began experimenting with cameras triggered by trip wires and, later, photoelectric cells to photograph tigers, bats, birds and other wildlife. But early efforts were severely constrained by clunky equipment that would waste film shooting falling twigs or flitting moths.

Over the last 15 years, though, the equipment has become far more sophisticated, rugged and easy to use, allowing biologists to record the passage of particular species at particular times of day and to train local residents to take over day-to-day work, retrieving film and reloading cameras. That gives biologists a new vantage point for studying animals and stretches their resources.

The camera equipment is particularly useful in tropical forests, where scientists can spend months or years studying wildlife in dense greenery and hardly ever see their quarry, said Dr. Ronald L. Tilson, the conservation director of the Minnesota Zoo and an expert on tigers.

''These cameras are going to revolutionize the study of tropical rain forest biology,'' Dr. Tilson said. ''You see so many more animals. It has certainly opened up a whole new view into the forest that we've never had before.''

During camera-trap surveys for tigers in southeastern Sumatra several years ago, his team unexpectedly gleaned pictures of the Sumatran rhino, one of the world's rarest mammals.

The equipment of choice is a set of infrared sensors and specialized weatherproof cameras sold under the brand name Trailmaster. Many of the biologists working with the devices note with an ironic chuckle that they were originally designed to aid hunters trying to get a feel for the regular movements of deer and other game.

Scientists now dominate the market for the cameras, which generally cost $400 to $650, said the product's inventor, Bill Goodson, who is based in Lenexa, Kan.

The next step, researchers hope, will be figuring out how to use cameras that can store long sequences of still or video images digitally and can transmit the data. That would eliminate the need for researchers to hike into the forest frequently to change film. But for the moment, digital cameras with disk drives consume too much power to be of practical use, Mr. Goodson said.

The cameras are being used in a variety of ways, ranging from quick preliminary wildlife surveys in developing countries to continuing projects designed to monitor the distribution and movements of tigers, leopards and other large predators.

They are particularly useful, biologists say, where surveys are made nearly impossible either by terrain or threats like rebel groups and tiger jaws.

In Myanmar, formerly Burma, biologists and trained local workers are conducting the first survey of wildlife in some of the world's most remote forests as part of a government effort to decide where to place new preserves and parks.

The hazards there range from rebels to one of the most drug-resistant strains of malaria on earth, said Dr. Anthony J. Lynam, a biologist with the Wildlife Conservation Society, a private group based at the Bronx Zoo. But extraordinary biological bounty is being revealed by the cameras, he said.

''Everything we're finding is brand new,'' Dr. Lynam said. ''This is because Myanmar is so unexplored. Nobody has been into these areas, so every photograph is new information.''

The cameras have been deployed in former and current war zones throughout Southeast Asia. In a park in northeast Cambodia, Dr. Lynam said, they are being used to track tigers. This is an area where poachers sometimes use explosives to kill tigers to supply the trade in Asian traditional medicines.

''They catch a pig or other game and tie it to some explosives,'' he said. ''A tiger takes the bait and blows up. They take the bag of bones and whatever else is left and sell it.''

In tiger studies in India and Indonesia, the cameras are allowing scientists to track not just general population shifts but also the movements of individuals, identified through patterns of stripes on their faces.

But the camera traps produce far more than just a rogue's gallery of passers-by, researchers say. They are increasingly being used as a statistical sampling tool, with several dozen devices set out in a grid around a large preserve. Over time, scientists can develop a clear picture of the movements of predators and prey.

Elsewhere, they are being used for more practical purposes.

In Belize, two lodges devoted to ecotourism have used the camera traps to get identifying snapshots of poachers.

In work on jaguars in Argentina and snow leopards in the Himalayas, biologists have been recording attacks on penned livestock to help villages protect their herds.

Darla Hillard, the program coordinator for the Snow Leopard Conservancy, a private group based in Los Gatos, Calif., said the rare leopards often raided stone pens where sheep and goats are kept at night. ''The cats will get in and because the panicked animals trigger their prey instincts, keep killing until there's no more movement,'' Ms. Hillard said. ''That's pretty devastating.''

By watching how the attacks take place, the researchers hope to help the villagers change the pen designs. In return, Ms. Hillard said, the scientists hope to be able to enlist the support of the local communities in conserving the predators.

Hunting the Poachers

Once in a while, a camera trap deployed to track wildlife snaps a picture of humans. The cameras are almost always positioned along game trails, so most of the pictures of people are of hunters -- often poachers. At left is a picture that researchers say could be the first ever of a member of Thailand's isolated Sakai tribe. At right are poachers entering a nature preserve on the Thailand-Cambodia border; at far right, Cambodian hunters. In Belize, pictures from camera traps are used to track down poachers.

Photos: A rare American crocodile is photographed during a late-night exploration of a Cuban beach. (Wildlife Conservation Society); A jaguar drags a pig into the forest after raiding a livestock corral in a remote part of Argentina. (Karina Schiaffino/Center for Subtropical Ecological Research); A muntjac, a small jungle deer, scampers along a trail in the Kaeng Krachan National Park. (Wildlife Conservation Society); An elephant in Thailand is caught in the act of destroying one of two automatic cameras. (Wildlife Conservation Society); A tiger is captured on camera in the Kaeng Krachan National Park on the border of Thailand and Myanmar. (Wildlife Conservation Society); (Photographs by Wildlife Conservation Society)